Rebirth in Fire

STUDENTS: Module 4: Forces in the Environment

Introduces the role of fire in revitalizing native plants and maintaining a healthy forest environment.

Wildland
fire is a natural process in the environment. In some areas, forest
managers use prescribed burns to maintain the healthy forest environment.
In order for people to appreciate the role of fire as a technique for
resource management, they must understand that fire can be beneficial
under the right conditions.

For fire to occur, three
elements must be present: heat, oxygen, and fuel.
These three elements form a ?fire triangle.?

Fuel
+ Heat + Oxygen = Combustion

Heat can be transferred in three ways:1. Radiation - heat is transferred by means of short energy waves.
2. Convection - heat is transferred through liquids and gases
by means of up-and-down movements called convection currents. 3. Conduction - heat is transferred by direct contact of molecules.

Characteristics of Fuel:1. Moisture - how well a fuel will ignite and burn is dependent
upon its moisture content or chemical composition.2. Size and shape - light fuels such as shrubs, grasses, leaves
and pine needles burn rapidly but are easily extinguished. Heavy fuels
such as logs and limbs burn more slowly.3. Fuel loading - the quantity of fuels in an area which is available
for combustion4. Horizontal continuity and vertical arrangement - the manner
in which fuels are spread over a certain area.

Characteristics of Weather:1. Temperature - fuel and ground temperatures are primarily due
to direct radiation from the sun2. Wind - encourages combustion and the spread of fire3. Relative Humidity - low humidity takes moisture from fuels;
fuels, in turn, take moisture from the air when humidity is high 4. Precipitation - fuel moisture is affected by the amount of
precipitation.

Characteristics of Topography:1. Aspect - the direction in which a slope faces relative to
the sun2. Slope - the degree of incline of a hillside. The steeper the
slope, the faster the fire burns up or down (depending on wind direction)3. The shape of the country ? box canyons, narrow canyons,
and other rugged topographic features can influence the wind?s
speed and direction.

It is essential that the public understand appropriate
fire management policies, and that fire is a necessary part of ecological
succession in many forested areas.

The objectives of prescribed burning are:1. fuel reduction2. preparation of seedbeds for regeneration of wind-disseminated
species which become established most readily on bare mineral soil3. control of competing vegetation4. improvement of grazing5. management of wildlife by allowing species that they feed
on to grow6. recreation management to maintain a park-like appearance7. thinning of saplings8. control of pestsThe key idea that needs to
be understood is that often it is most efficient to ?fight fire
with fire;? that is, allow the proper authorities to set fires
deliberately so as to avoid larger and more destructive fires in later
years.